Stripe SDK integration using swift and flutter

Question

I am trying to integrate Apple Pay in iOS using flutter. I am using method channels to communicate with swift and get the payment process completed. I have followed the documentation which is in this link

However, I believe I have stuck in the very ending part which I don't understand how to continue the flow. Since I am using flutter UIs, I don't need iOS ViewControllers.

This is the code that I have tried so far in the AppDelegate.swift:

func handleApplePayButtonTapped(result: FlutterResult){
    let merchantIdentifier = "my.apple.merchant.id"
    let paymentRequest = Stripe.paymentRequest(withMerchantIdentifier:merchantIdentifier, country:"US", currency:"USD")
    paymentRequest.paymentSummaryItems = [
    PKPaymentSummaryItem(label:"Fancy Hat", amount:50.00),
    PKPaymentSummaryItem(label:"iHats, Inc", amount:50.00),
    ]

    if Stripe.canSubmitPaymentRequest(paymentRequest){
        //next steps ???
        result(String("Can submit payment request"))
    }else{
        result(String("Can't submit payment request"))
    }
}

I am calling this code in flutter UI using this code:

Future<void> _doPayment() async {
String returnMsg;
try {
  final bool result = await platform.invokeMethod('checkIfDeviceSupportsApplePay');
  if(result){
    final String status = await platform.invokeMethod('handleApplePayButtonTapped');
    print(status);
  }
  returnMsg = '$result';
} on PlatformException catch (e) {
  returnMsg = "Failed: '${e.message}'.";
}
print(returnMsg);}

I already have a Stripe publishable key as well as a Heroku deployed backend. If you checked my swift code, you will see where I am stuck at the moment.

As I have understood the flow, what is remaining to be done is

• send the card details to the backend and get a token
• using the token, send the payment details to the Stripe server

I am very new to swift language and code samples will be greatly helpful for me to continue with.

Thank you.

Solution

It looks like you're following the Stripe Custom iOS Integration, using the native PKPaymentAuthorizationViewController.

You should read through the integration steps here: https://stripe.com/docs/mobile/ios/custom#apple-pay

Basically, your next steps would be

• instantiate a PKPaymentAuthorizationViewController with the paymentRequest
• Set yourself to its delegate
• present the PKPaymentAuthorizationViewController
• implement the relevant delegate methods to get back an Apple Pay token (PKToken)
• convert PKToken to STPToken (a Stripe token)

All these steps and more are detailed in the link above.

Comments

[Sajad Jaward]

thank you for the clarification. Would you be able to provide a sample implementation for the submitTokenToBackend() method? that would be greatly helpful.

[hmunoz]

@SajadJaward that entirely depends on how your client<>server communication works. But basically you would post your token ID over to your server-side endpoint. Your server-side endpoint would parse the token and create a Charge on Stripe. And then return a response to your client's request, for your app to display on the client-side